Method of making a tubular product



July 5, 1938. A 5, LYNCH 2,122,481

METHOD OF MAKING A TUBULAR PRODUCT Filed Dec. 2. 1935 YW /Zzf Patented July 5, 1938 UNITED STATES PATENT OFFICE 2,122,481 nm'rnop or MAKING A mums raonuc'r Albert S. Lynch, Beaver, Pa., assigner to Jones & Laughlin Steel Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Application December 2. 1935, Serial No. 52,481 3 Claims. (Cl. 29-156) This invention relates broadly to tubular prod- Inward upsetting therefore has an important ucts and the manufacture thereof, and more advantage in reduction of the cost of producing particularly to the formation of tubular products the upset pipe. 'I'his advantage is so important by upsetting. It relates still more particularly that it is from the commercial standpoint neces- 5 to a method of forming a pipe section having an sary to produce pipe sections having integral integral coupling portion and to a novel pipe coupling portions by inward upsetting. Sections section of such character. produced by outward upsetting only could never r It has been proposed to make pipe in sections be sold at a price even approaching their cost, with integral coupling portions on the respective so that this method is commercially worthless.

sections by upsetting the pipe ends to form the However, inward upsetting has the disadvantage l0 integral coupling portions. Pipe of this charabove mentioned of constriction of the bore. acter is especially well adapted for use as drill This is highly undesirable as it seriously impedes pipe for drilling wells. In my copending applithe ow of fluid through the pipe and greatly cation Serial No. 739,122, filed August 9, 1934, reduces the eiciency of the pipe.

L there is disclosed and claimed a. method of form- Moreover, in upsetting pipe a mandrel is eming a tubular product of the character above ployed which during the upsetting extends Within mentioned and a drill pipe section having certain the pipe and assists in shaping the upset metal. novel features. In order to enable withdrawal of the mandrel A disadvantage of pipe sections having integral without damage to the work the mandrel is made gg upset coupling portions as heretofore produced is tapered. Ordinarily the mandrel forms a part of the constriction of the bore of the section paused the upsetting tool and passes into the pipe to be by upsetting. It is not possible in a single upupset` ahead of the portion of the tool which setting operation in which the metal is caused to contacts the end of the pipe to perform the upilow only outwardly. or away from the pipe axis, setting operation, the mandrel being tapered to g5 to increase the wall thickness over about 30 per minimum diameter at its forward extremity. 'I'he 25 cent. An attempt to do so results in a grain mandrel is designed so that the upset product structure in the metal which is unsatisfactory, will have the desired wall thickness at the portion and a product thus produced is of no practical of the mandrel ci' relatively great diameter, revalue. On the other hand, it is possible in a sulting in constriction of the bore toward the single upsetting operation in which the metal is forward extremity of the mandrel. This con- 250 caused or allowed to iiow inwardly, or toward the striction is in many cases highly undesirable and pipe axis. to increase the wall thickness up to or disadvantageous, not only because it impedes fluid slightly over 150 per cent. and still produces. how through the upset pipe. but also because, due strong commercially satisfactory product having to the conditions imposed in upsetting, the wall the proper grain structure. thickness of the upset pipe at the point of mini- 3 Consequently, in the production of pipe of the mum diameter of the mandrel may be considercharacter here concerned with it is not feasible ably greater than desired.

to upset externally only. as a considerable num- FOI' example. it iS not possible by any comber of upsetting operations and intermediate remercially practicable method heretofore em- 40 heatings would be necessary which would in- Dloyed to form a pipe section having an integral 40 crease the cost of the pipe out of all proporupset coupling 1301121011 having the desired intion to its value. Therefore, internal upsetting 2mal Rnd external Shape and the desired wall is resorted to. A satisfactory pipe section havthickness Bt all POintS M0118 the tapered mandrel. ing an integral upset coupling portion can be It has not been possible to produce commercially Cri produced in this way by a comparatively small drill pipe with integral upset coupling portions 45 number of upsetting operations. as, for example, and 0f unifOIm bOIe. Which is and has fOr years one, two or three. It is preferable to use either been recognized BS being the most highly desirtwo or three upsetting steps, but this compares able form of drill pipe. favorably with the number of steps which would The problems above mentioned have long been o be required if an attempt should be made t0 recognized but no satisfactory solution thereto 50 form the section by external upsetting only. At has hel'eOfOl'e been f0l1nd- All example of a least fourb and probably ilve or six, upsetting theoretical suggestion for the formation of unisteps with intermediate reheatings would be form bore integral joint upset drill pipe is the i necessary to form the section by external upupsetting of the extremities of a drill pipe section setting only. externally only so as to avoid constriction of the` 56 similarly removing a portion bore. However, as explained above, this proposal is not commercially feasible, Pipe produced according to this suggestion could never be marketed. Moreover, I understand it to be the fact that pipe has never been made in accordance with such suggestion either commercially or noncommercially. Such suggestion simply represents a theoretical paper scheme. This suggestion is of interest, however, as showing recognition of the problem which applicant has solved.

In the formation of pipe of the character in question in which the wall thickness of the upset' portion is to be at least 30 per cent. greater than the wall thickness of the pipe it is necessary in commercial operation, as above explained, to upset the metal inwardly or toward the axis of the pipe. I prefer to utilize the method of upsetting disclosed in my said application, rst inwardly upsetting the metal in either one or two steps and then outwardly upsetting. However, the ultimate upset product has a constricted bore and a wall portion of unnecessarily great thickness. In certain cases such constricted bore and thick wall portion are not particularly undesirable but in other cases they are highly undesirable, and. it is a purpose of the present invention to obviate the disadvantages mentioned.

I preferably upset an end of a pipe section whereby to increase the wall thickness and reduce the internal diameter thereof and thereafter reshape the interior of at least the part of the upset portion which is of least internal diameter to' reduce the restrictive eifect imposed thereby. I preferably accomplish the reshaping by removing material from the interior of the upset portion. Such removal is preferably effected by a machining operation, and I ilnd it especially desirable and convenient to bore out at least part of the upset portion. In this manner I am able to render the bore of the upset portion of the section of substantially constant diameter forat least a substantial distance longitudinally of the section, and the bore of the upset portion may berendered of substantially constant diameter and, if desired, of the same diameter as the bore of the non-upset portion of the section. In one preferred method of carrying out the invention presently to be described I form in a commercially drill pipe having a substantially uniform bore throughout. So far as I am aware, this is the first time that upset integral joint uniform bore drill pipe has ever been produced either commercially or non-commercially. Heretofore when uniform bore drill pipe has been specified separate couplings have been used which are relatively expensive, far more difficult to assemble and much less satisfactory in use.

Pipe made by upsetting and then boring out or of the material from the interior of the upset portion may readily be identiiied by the machined surface at at least a portion of the bore. Such machined surface is also of advantage in reducing the friction losses suffered by fluid passing through the pipe. While the friction loss in any one section of pipe may not be great, when it is considered that a large number of sections are coupled together in use the friction loss is an important factor.

Other details, objects and advantages of the invention will become apparent as the following description of certain present preferred embodiments thereof and certain present preferred ,methods of practicing the same proceeds.

In the accom drawing I haveshown certain present preferred embodiments of the invention and .have illustrated certain present preferred methods of practicing the same, in which Figure 1 is a central longitudinal cross-sectional view through a portion of an upset blank used in the formation of a pipe section;

Figure 2 is a similar view of the blank shown in Figure l but with a portion of the interior thereof reshaped; and

Figures 3 and 4 are views corresponding respectively to Figures 1 and 2 showing a different form of structure.

Referring now more particularly to the drawing, Figures 1 and 2 illustrate the formation of an integral coupling portion for the box or female end of a pipe section while Figures 3 and 4 illustrate the formation of an integral coupling portion for the pin or male end of the section. The method used in either case is substantially the same.

Referring nrst to the form of Figures l and 2. there is provided a length of pipe of suitable characteristics and whose initial wall thickness may be as shown at the left-hand extremity of Figure l. The end of the pipe length or section is preferably heated for a suitable distance from its extremity, as Well known in the art, and is then subjected to one or more upsetting operations which may be, and preferably are, substantially the same as or similar to the upsetting operations described and illustrated in my said copending application. The end of the section or blank after completion of the upsetting is shown in Figure 1 and is designated generally by reference vnumeral 2. 'I'he external diameter is increased to the desired extent as shown at 3 and the internal diameter is controlled as desired at the point l which coincides with the portion of relatively great diameter of the tapered length of the mandrel used in the upsetting step. The point corresponding with the extremity of such tapered length of the mandrel is indicated at E. The diameter of the bore of the upset section than at the point l, although this may be undesirable in the finished product due to the constrictive effect, the relatively'great amount of material iembodied in the section and the increased weight thereof.

I reshape the interior of the upset portion of the section, as explained above, preferably by boring, and the bored-out section is shown in Figure 2. The material included between the chain line B and the inner surface ofthe section has been removed, rendering the bore of the entire section substantially uniform from end to end. I thus produce integral joint uniform bore drill pipe by a method which is practicable from the commercial standpoint. As stated above, although uniform bore integral joint drill pipe Vhas been sought for many years, it has never before, so far as I am aware, been produced commercially or even non-commercially.

Figures 3 and 4 are exactly analogous to Figures 1 and 2 showing the male end of the section. Parts of Figures 3 and 4 corresponding is .materially less at the point 5* respectively with parts of Figures l and 2 are designated by like reference numerals each having a prime The upset pipe as shown in Figures 2 and 4 may be subjected to desired after-operations such as heat treatment, threading and nnishing. Howeve the pipe formed as above described is of the desired shape and no further modiiication in respect of its shape either internally or externelly is n.

While I have shown and described certain present preferred embodiments of the invention and certain present preferred methods of practicing the same. it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

I claim:

1. A method of making an upset integral ioint drill pipe section of substantially uniform bore. comprising heating a generally tubular blank. upsetting an end portion of the blank both internally and externally whereby to decrease its internal diameter and increase its external diameter. such upsetting operation entailing relatively few upsetting and reheating operations as compared with those which would be necessary if the blank were upset outwardly only, increasing the external diameter oi the blank by such up setting sumciently that substantially the amount of metal necessary for formation of an integral pipe joint lies outside a cylinder denned by the original internal diameter of the blank. and reshaping the blank tc enlarge the reduced internal diameter thereof at said upset portion to substantially the internal diameter of the non-upset portion of the blank.

2. A method of making an upset integral Joint ly few upsetting and reheating operations as compared with those which would be necessary i! the blank were upset outwardly only, increasing the external diameter of the blank by such upsetting suiliciently that substantially the amount of metal necessary for formation of an integral pipe joint lies outside a cylinder dened by the original internal diameter of the blank, and removing material from the interior of the blank at said upset portion to enlarge the reduced internal diameter thereof at said portion to substantially the internal diameter of the non-upset portion of the blank.

3. A method of making an upset integral joint drill pipe section of substantially uniform bore, comprising heating a generally tubular blank. uptting an end portion of the blank both internaliy and externally whereby to decrease its internal diameter and increase its external diameter. such upsetting operation entailing relatively few upsetting and reheating operations as compared with those which would be necessary if the blank were upset outwardly only, increasing the external diameter oi the blank by such upsetting suiiiciently that substantially the amount of metal necessary for formation o! an integral pipe `iolnt` lies outside a cylinder denned by the original internal diameter of the blank. and boring out of the blank at said upset portion to enlarge the reduced internal diameter thereof at said portion to substantially the internal diameter of the non-upset portion of the blank.

ALBmT S. LYNCH. 

